Image pickup devices are usually used to take photographs or record video data. In addition, image pickup devices are applied to web cameras for holding a video conference. Recently, the commercially available notebook computer is usually equipped with a built-in image pickup device.
With increasing development of digital techniques, text documents are gradually created as electronic files. Generally, text documents are scanned by scanning apparatuses and then saved as electronic files such as PDF (Portable Document Format) files. In a case that no scanning apparatus is communicated with the notebook computer, the images of simple documents such as single-sided papers or business cards may be captured by the built-in image pickup device. The images captured by the built-in image pickup device are usually saved as JPEG (Joint Photographic Experts Group) files. Most users prefer using scanning apparatuses to scan the text documents as PDF files because the texts and signs contained in the PDF files are readable by the computer systems and may be converted as editable text files.
As known, optical character recognition (OCR) is a process of capturing an image of a document and then extracting the texts from that image. It is possible to analyze images that are captured from the image pickup device by the OCR technique and saved as JPEG files. As a consequence, individual texts or signs contained in the JPEG files are recognized and converted as editable text files. Since the associated OCR techniques are well established, the image pickup device is gradually adopted to obtain electronic files of the documents.
When an image pickup device of a notebook computer is used to capture the image of a document, some difficulties possibly occur. For example, it is critical to hold the document steady. For capturing the image of an article contained in the document by the image pickup device of the notebook computer, if this document is held by the user's hand, the document is readily rocked due to the long holding time. Under this circumstance, the obtained document image is usually blurred. For preventing from rocking of the document and thus obtaining a sharp document image, a static document stand is used for holding the document steady. The use of the document stand, however, incurs another problem. In a case that the document stand is used in other places, the user should carry the notebook computer and the document stand at the same time, which is very troublesome to the user.
For convenience, the document is directly placed on a working plane (e.g. a desk plane) without the need of the document stand. After the document is placed on a proper location of the working plane, the upper cover of the notebook computer is rotated such that the image pickup device is aligned with or close to the document. Meanwhile, the image of the document may be captured by the image pickup device. When the image pickup device of the notebook computer is used to capture the image of the document placed on the working plane, some drawbacks also occur. The common drawback is occurrence of a distorted image. If the shooting range of the image pickup device is insufficient, the image captured by the image pickup device for a single time is usually incomplete. For solving this drawback, the user usually takes photographs of the document for two times in order to obtain two incomplete images. By means of image processing techniques, these two incomplete images are combined together. In other words, after the upper-half portion of the document is captured by the image pickup device, the document should be moved such that the lens of the image pickup device is aligned with the lower-half portion of the document and the image of the lower-half portion is captured. Since there is no reliable reference tool or reference point on the document, the document is readily aslant during movement of the document. Consequently, the document after being moved fails to be parallel with the original location of the document. Under this circumstance, the image of the lower-half portion of the document is distorted and is unsuccessfully combined with the upper-half portion of the document. For obtain a sharp image, it is necessary to re-capture the document. In other words, the distorted image is troublesome to the user.
Recently, a commercially available notebook computer has a fixing recess for securely fixing a business card on a proper position. The fixing recess is disposed in the front edge of the case of the notebook computer. After the card is received within the fixing recess, a sharp image of the business card will be captured by the image pickup device. The notebook computer with the fixing recess is applicable to capture the images of business cards. In other words, since the documents having a size larger than the business card fails to be sharply captured, these relatively larger documents are unable to comply with user's requirement.